Fan structure

ABSTRACT

A fan structure includes a base having a receiving section; a sleeve defining a receiving space therein, and having a shaft hole communicating with the receiving space and an engaging end for engaging with the receiving section of the base; a bearing having an axial bore and received in the sleeve; and an insulating rack externally fitted around the sleeve and having a holding section for holding at least one silicon steel plate set therein, which is spaced from the sleeve by at least one first space. With these arrangements, heat produced by the silicon steel plate set during fan operation is isolated by the first space from directly damaging the bearing. 
     Further, since the bearing is stably held in place in the sleeve without the need of using any bonding material, the fan structure can have extended service life and reduced manufacturing cost.

FIELD OF THE INVENTION

The present invention relates to a fan structure, and more particularly to a fan structure having a sleeve stably holding at least one bearing therein and being surrounded by an insulating rack to isolate heat from the bearing.

BACKGROUND OF THE INVENTION

Most general 3C electronic products would produce a large amount of heat during the operation of internal electronic elements thereof. The internal electronic elements are subject to burnout and damage when they are in a constantly high-temperature state. To avoid the electronic elements from becoming damaged, at least one heat dissipating unit, such as a heat radiating fin assembly or a heat sink, and a fan device are used to dissipate the heat produced by the electronic elements during the operation thereof, so as to increase the service life of the electronic elements.

FIG. 1 is an exploded perspective view showing the structure of a prior art fan 9. As shown, the fan 9 includes at least on rotor 91, at least one stator assembly 92, at least one bearing 93, and a frame 94. The bearing 93 has an axial bore 931; the frame 94 has a sleeve 941 for receiving the bearing 93 therein; the rotor 91 has a shaft 911 and a plurality of blades 912 spaced around the rotor 91, and the shaft 911 is inserted into the axial bore 931 of the bearing 93; and the stator assembly 92 includes a silicon steel plate set 921 and a plurality of insulating plates 922. The stator assembly 92 is directly externally fitted around the sleeve 941. When the fan 9 operates, the silicon steel plate set 921 of the stator assembly 92 will produce heat, and the produced heat is transferred from the silicon steel plate set 921 to the sleeve 941, which is fitted in the stator assembly 92. The heat is further transferred from the sleeve 941 to the bearing 93 received in the sleeve 941. When the bearing 93 is heated, lubricating oil contained in the bearing 93 is evaporated, resulting in dry friction between the shaft 911 and the bearing 93 to damage the fan 9.

Therefore, the prior art fan structure has the following disadvantages: (1) having short service life; and (2) heat being easily accumulated at the bearing and the sleeve.

SUMMARY OF THE INVENTION

A primary object of the present invention is to provide a fan structure that is able to isolate heat produced during the fan operation from a bearing of the fan, so that the bearing is not damaged by the heat.

Another object of the present invention is to provide a fan structure that is able to stably and accurately hold a bearing in place.

To achieve the above and other objects, the fan structure according to the present invention includes a base, a sleeve, at least one bearing, and at least one insulating rack. The base includes a receiving section. The sleeve defines a receiving space therein, and has a shaft hole communicating with the receiving space and an engaging end for engaging with the receiving section of the base. The bearing has an axial bore and is received in the receiving space in the sleeve. The insulating rack is externally fitted around the sleeve and has a holding section for holding at least one silicon steel plate set therein. The silicon steel plate set is spaced from the sleeve by at least one first space. With the insulating rack being directly fitted around the sleeve and the silicon steel plate set being spaced from the sleeve by the first space, heat produced by the silicon steel plate set during the operation of the fan is isolated by the first space from directly damaging the bearing. Further, since the bearing is enclosed and stably held in place in the sleeve without the need of using any bonding material, the fan structure can have extended service life and reduced manufacturing cost.

In brief, the fan structure of the present invention has the following advantages: (1) having extended service life; (2) allowing the bearing to accurately located in place; (3) saving the cost for bonding material; and (4) isolating the bearing from heat.

BRIEF DESCRIPTION OF THE DRAWINGS

The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein

FIG. 1 is an exploded perspective view of a conventional fan structure;

FIG. 2 is an assembled sectional view of a fan structure according to an embodiment of the present invention; and

FIG. 3 is an exploded sectional view of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please refer to FIGS. 2 and 3 that are assembled and exploded sectional views, respectively, of a fan structure according to an embodiment of the present invention. As shown, the fan structure includes a base 1, a sleeve 2, at least one bearing 3, and at least one insulating rack 4. The base 1 includes a receiving section 11. The sleeve 2 defines a receiving space 21 therein, and has a shaft hole 22 communicating with the receiving space 21 and an engaging end 23 for engaging with the receiving section 11 of the base 1. The bearing 3 has an axial bore 31, and is received in the receiving space 21 in the sleeve 2. The insulating rack 4 is externally fitted around the sleeve 2, and has a holding section 41 for holding at least one silicon steel plate set 6 therein. The silicon steel plate set 6 and the sleeve 2 is spaced from each other by at least one first space 25. The insulating rack 4 is directly fitted around the sleeve 2, and used to hold the silicon steel plate set 6 thereto. Since the silicon steel plate set 6 is spaced from the sleeve 2 by the first space 25, heat produced by the silicon steel plate set 6 during the operation of the fan is isolated by the first space 25 from directly damaging the bearing 3. Further, since the bearing 3 is enclosed in the sleeve 2, the bearing 3 is stably held in place in the sleeve 2 without the need of using any bonding material to save the cost therefor. Thus, the fan structure of the present invention can have extended service life and reduced manufacturing cost.

The bearing 3 has a shaft 5 inserted therein. The shaft 5 has an end extended through the shaft hole 22 on the sleeve 2 into the axial bore 31 of the bearing 3, and an opposing end connected to a rotor 7 with a plurality of blades 71. The shaft 5 is tightly fitted in the axial bore 31 of the bearing 3 and then disposed in the sleeve 2. The shaft hole 22 and the axial bore 31 are communicable with each other. The engaging end 23 is located at an end of the sleeve 2 opposite to the end with the shaft hole 22. The base 1 further includes at least one oil reservoir 12.

The insulating rack 4 further includes a first receiving recess 42 and a second receiving recess 43. The holding section 41 is located between the first and the second receiving recess 42, 43. A plurality of windings 24 is wound the insulating rack 4 in the first and the second receiving recess 42, 43.

The present invention has been described with a preferred embodiment thereof and it is understood that many changes and modifications in the described embodiment can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims. 

1. A fan structure, comprising: a base including a receiving section; a sleeve defining a receiving space therein, and having a shaft hole communicating with the receiving space and an engaging end for engaging with the receiving section of the base; at least one bearing each having an axial bore and being received in the receiving space in the sleeve; and at least one insulating rack being externally fitted around the sleeve, and having a holding section for holding a silicon steel plate set therein; and the silicon steel plate set being spaced from the sleeve by at least one first space.
 2. The fan structure as claimed in claim 1, wherein the silicon steel plate set and the insulating rack are externally wound by a plurality of windings.
 3. The fan structure as claimed in claim 1, wherein the insulating rack includes a first receiving recess and a second receiving recess, and the holding section being located between the first and the second receiving recess.
 4. The fan structure as claimed in claim 1, wherein the base further includes an oil reservoir.
 5. The fan structure as claimed in claim 1, wherein the bearing has a shaft inserted therein, and the shaft having an end extended through the shaft hole on the sleeve into the axial bore in the bearing, and an opposing end connected to a rotor of the fan structure. 